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Signs of a Blown Head GasketNote: You can only truly confirm your suspicion by actually seeing the gasket, although precursor signs are usually evident.

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If you see coolant leaking from the water pump, I would pressure-test it and pinpoint the leak and fix that first; oil seepage isn't necessarily abnormal.

Typical symptoms of a blown head gasket may include these: bubbles of air coming up into your radiator (remove cap before starting); a leaking radiator; milkshake-colored oil; overheating; rough running; coolant or oil running from head; spark plug(s) that have a green tint (if green coolant); white-colored or sweet-smelling exhaust.

White smoke from your tail pipe, or loosing coolant through your overflow. Take the cap off and rev the engine: if you see bubbles, or if it comes out, you'll know.

A blown head gasket will leave a dark smell in the radiator. And you will have high back pressure coming though your radiator cap.

Take your car to a radiator shop to have a detector installed: If the blue liquid inside a "bulb" turns yellow, you have a leak.

Beware that if you drive for too long and it overheats, a blown engine will be your outcome.

A blown head gasket can go out in different areas causing different symptoms. Do a compression test to give you some idea. Don't confuse low compression for a bad head gasket, though. A bad valve can lower compression. And a bad ring.

There are lots of clues you can look for. When in doubt and you have tried everything, have the head checked out by a well-established machine shop first, to see if the head was the problem. This way you're not wasting your time replacing the gasket.

My car once had a blown head gasket. I had a great deal of coolant loss. The engine lacked power and ran poorly. It had white smoke coming out the tail pipe. And it overheated very quickly. Also, it had water in the oil.

A quick way to check: Look at your spark plugs; if coolant squirts out, you definitely have a blown head gasket!

Low compression does not necessarily mean a blown head gasket, but it is a good indicator if there is a sharp drop in compression on one or two cylinders, with no drop in the others. Sometimes a blown head gasket will cause a whistling or wheezing sound, but not always. It will not always cause water to enter the oil - or oil to enter the water - but they are signs to look for. Overheating will almost always occur, due to the exhaust entering the coolant. Check your overflow bottle for exhaust smells. Watch for bubbles or overflow of coolant from the radiator while running the engine. Check for muddy gray-looking oil or bubbles on the dipstick.

Often (but not always), a blown head gasket will also cause deposit of water on a piece of cardboard held an inch from the tailpipe output while the engine is running (when this is happening, it is likely that the catalytic converter has been ruined and the muffler will corrode in short order as well). Sometimes drops of water will be seen dropping from the end of the tailpipe.

Another clue: Turn on the heater; often when the head gasket is blown an odor of antifreeze and synthetic rubber will emanate from the heater vents.

Many of the symptoms of a blown head gasket can be caused by some other problem in the cooling system, without the head gasket being damaged. Conversely, other problems with the cooling system can cause a blown head gasket and/or warped head. For example, a corroding radiator can send chunks of rust through the cooling system which take out the thermostat and water pump. If the thermostat is old, sticking and corroding, it can send those chunks through the system and take out the water pump or cause a blockage in the radiator, etc.

Radiator leaks can be the primary cause, or a result, of failures in other cooling system components.

Don't keep driving with the car overheated, especially if your engine has an aluminum head; you are likely to warp it. If it is warped beyond a certain tolerance, it cannot be planed and will have to be replaced when the head gasket is replaced.

One of the most common tell-tale signs is a milky-gray ring around your oil cap. When coolant enters the engine oil through a crack in the head or through a blown gasket, it evaporates and leaves a milky ring around the oil cap. Another easy way to tell is to check your oil dipstick. Change your oil and pull out the dipstick. Make sure that you take note of how far up the dipstick the oil is. Top off your cooling system and fill your cooling reservoir to the top. Screw radiator cap back on and start engine. Run engine for about 20-30 minutes or until it reaches normal operating temperature. Allow engine to cool (engine must cool completely to get accurate oil reading). Check oil dipstick again. If the oil has a watery appearance and has risen noticeably up the dipstick, then you probably have a blown head gasket or a warped head. Also, look for a sweet-smelling liquid coming out of your tailpipe. Any of the above symptoms could be the result of a blown head gasket.

The easiest way to tell is with a compression meter. This replaces the spark plug and lets you know what compression each cylinder is running at. If your compression is abnormally low, then you have a blown head gasket or a warped head. (Note: check the repair manual for appropriate compression of each cylinder.)

This can be detected in a variety of ways: One way is to note whether that part of the engine block is leaking fluid. This is difficult to determine since there are many other parts of the engine nearby that can also leak fluids, especially when a vehicle is parked in one place for more than a few hours. One of the best indications of a blown, or nearly blown, head gasket in most automobiles is when the cooling system appears to be malfunctioning. The cooling system's efficiency and performance can be directly affected by the quality of the head gasket.

If your radiator is getting low on water often, this is a sign. The water could be discharged through the tailpipe on your automobile. Another sign is if your car motor has a miss in the engine. The water could be going in on top of the cylinders. This will foul the plugs and cause it to miss.

There are a few simple indicators you can check for with the engine cold and not running: 1) contaminated oil - it will have a milky appearance from the water mixing in the oil 2) oil on the top of the coolant inside the radiator (if your vehicle has a remote header tank you may not get this); 3) Have someone crank (remove the coil lead or disable the electronic ignition) the engine on the starter with the radiator cap or coolant jacket bleed hose/bolt removed. If the coolant pulses up and down or blows bubbles, you could be in trouble. If you find any of these symptoms move on to removing the spark plugs (label the plugs and the leads as you remove them, so you can put them back in the same place) and again crank the engine on the starter. Depending on how badly your head or gasket is gone, you may get coolant or oil coming out of the plug holes. Inspection of the plugs will also reveal problems during combustion: if you have rusty flaky deposits on the plugs, you may be burning off water; and if you have a heavy carbon, you are burning oil. If you have any of the first 3 items listed (water in oil, oil in water, or pulsing coolant - but don't get any result from checking the plugs) change the oil and water as appropriate, then warm up the engine without the radiator cap on (or the bleeder hose/bolt) and watch for bubbles as the engine warms up. Put the cap back on the cooling system and take the vehicle for a short drive, or run the engine till the entire system is up to temperature and then check the oil for contamination. Having these symptoms is not always indicative of a blown head gasket; usually if the gasket is gone, there is going to be some warping of the head and or block of the engine.

Loss of engine coolant with no external leaks, a continuous stream of bubbles can be seen with the radiator cap off, black gummy and sometimes crusty stuff around the radiator

Several common signs of a blown head gasket:

Blue/white smoke coming out the tail pipe which indicates oil is burning

Dripping oil from the gasket itself

Carbon Monoxide or hydrocarbons in the cooling reservoir

Excessive coolant loss with no obvious source of leakage

Loss of power or a rough engine due to compression loss

Water mixing with oil

Oil mixing with water

Low compression in 2 or more adjacent cylinders

Remove dipstick and let a drop of fluid fall on hot part of engine - oil will smoke water will "sizzle"

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Gerald Clay

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Retired from USPS and now working as electrician. Love cars and still work on them in my spare time. Also a member of the Patriot Guard.

Answer .
\nA blown intake gasket will cause the engine to run too lean, which in turn will cause drivablity problems. A blown head gasket on the other hand may or may not e…ffect the drivablity of the vehicle and may not set the check engine light. Serious engine damage will occur if you continue to drive a vehicle with a blown head gasket. You can see any or all of these symptoms. White smoke coming from the exhaust, A sweet smell at the exhaust, Loss of coolant, Coolant in the oil, air bubbles in the radiator, engine miss. Either of these conditions may or may not set the check engine light.

Gerald Clay

60,873 Contributions

Retired from USPS and now working as electrician. Love cars and still work on them in my spare time. Also a member of the Patriot Guard.

Answer .
\nOverheating, miss on one or more cylinders, loosing coolant with no apparent leak, sweet smell at the exhaust pipe, air bubbles in the radiator with the cap off…, coolant mixed with the oil, milky substance on the underside of the oil cap, are just some of the symptoms.

FINDING A RECENT POST MADE BY AN INEXPERIENCE PERSON MISLEADING THE PUBLIC, I NOW FEEL I MUST REMIND OTHERS THAT........ Blown head Gaskets are NOT BLOWN by the oil reservoir… being filled to much. A high level of oil will NOT increase oil pressure. An oil pump has a set amount of pressure allowed and no matter how much oil you over fill it, it will not increase pressure. It may make a mess or cause the engine to smoke BUT IT WILL NOT BLOW HEAD GASKETS. A head gasket typically blows from an engine that is running overly hot and it's coolant has lost the ability to keep temperature below normal levels. Loss of coolant. This causes an engine to get overly hot and expand to much. The two mating surfaces of the Engine Block and Cylinder Head where the gasket lays may expand away from each other and/ or the head itself may warp slightly causing the oil , coolant, or both to leak into each other or into the combustion chamber. Some may think that if there is no water in the oil, or vice-a-verse then it can't be the head gasket. That can't be further than the truth. The gasket keeps the OIL , the COOLANT, & the COMBUSTION CHAMBER separate from one another. If an engine hasn't been properly maintained , like the oil changed regularly & the coolant system flushed & clean, it will develop contaminants and cause deterioration of the gasket. This will eventually cause a gasket to fail. Because of the water jacket ( or ports) and the the combustion chamber being in such close proximity, a gasket failing between those two areas, will cause only the coolant to escape and it go into a combustion chamber. The coolant will immediately turn to steam and go out the exhaust without the driver knowing until it is to late. During this phenomena, because the head is so extremely hot in the area of the exhaust valve , the sudden change in temperature from the coolant hitting the head may also cause the head to crack in a place where the metal is thinner. The crack itself may then go across two areas of critical importance where a sudden change in engine performance alerts the driver of a problem. The same applies to the oil jacket. It may leak into the combustion chamber but immediately will burn and cause a smoke to develop out the exhaust, giving warning. Because both water & oil don't belong in the combustion chamber, the engine may start to misfire and/ or run poorly, giving a driver a false sense that a tune-up is all that may be needed. It is important to regularly flush a coolant system & maintain clean oil and their levels to prevent catastrophic failure that can lead to thousands of dollars in repairs.

General signs of a blown head gasket: Oil mixing with water water mixing with oil Run engine to normal operating temperature Remove dipstick and let a drop of fluid fa…ll on hot part of engine - oil will smoke water will "sizzle" White smoke from tail pipe

Usually a blown head gasket will allow cooling water to enter the affected cylinder. This can be detected by observing the spark plugs for water on the electrode, or a clean w…ashed appearance. A gasket blown between cylinders, may show no sign of water, but depending on size of the engine, may be hard, or impossible to start. The quickest, and most sure way to find out, is a compression reading of all cylinders.

If you have a bad head gasket , or the head is warped or cracked , you can get coolant in your oil and/or into the engine cylinders so you get white smoke coming out of your e…xhaust even when the engine is warmed up ( I'm not a mechanic / technician , I'm sure a professional can tell you more ) I have been buying cars and vans that have blown head gaskets for myself at a reduced cost and I have had great success repairing them without disassembling the engine. Its very simple to use and is a permanent repair. It costs 20.00 and its added to the radiator. It mixes with antifreeze and does work if you follow the simple directions. My cousin has a garage and has been using this stuff. Its very hard to find and is not found in part store's if you want any email me kerisvery@aol.com Sealed up a blown head gasket and cracked block.Thanks Carl Shilanskis1995 corsica 3.1 with a blown head gasket, 3k miles and so far so good. Hope its stays that way. Fred

loosing coolant without leaking under the car, so it is burning coolant, mine is staying on and so is engine light and it is also a 99 grand am gt and just happened today :( n…ow we to put upper gaskets in.

Charlie N.

122,923 Contributions

I have spent many years renovating buildings and leading a commercial handyman crew.

Loss of coolant with no apparent leak, engine overheating, oil level overfull, white smoke from the exhaust especially at start-up that smells sweet, a white/grey foamy substa…nce on the underside of the oil fill cap, air bubbles escaping from the radiator with cap off engine running, & possible engine miss.

Gerald Clay

60,873 Contributions

Retired from USPS and now working as electrician. Love cars and still work on them in my spare time. Also a member of the Patriot Guard.

Not sure if your question is comparing the two situations, however, let me say a bit. A blown head gasket and a crack head has similar symptoms. Depending on the area of damag…e they can show signs like heating issues, cylinder misfire, oil & coolant mixes and even excessive crankcase pressure. Doing specific test can narrow exactly what is happening and what area. they are pretty much the same in terms of symptoms.

Gerald Clay

60,873 Contributions

Retired from USPS and now working as electrician. Love cars and still work on them in my spare time. Also a member of the Patriot Guard.

Engine overheating, engine miss, loss of coolant with no apparent leak, white smoke from the exhaust, oil level overfull, oil has a grey or brown color, a white foamy substanc…e on the underside of the oil fill cap, air bubbles escaping from the radiator with engine running cap off. Any or all of these symptoms indicate an blown head gasket.

Gerald Clay

60,873 Contributions

Retired from USPS and now working as electrician. Love cars and still work on them in my spare time. Also a member of the Patriot Guard.

Sometimes. Symptoms of blown head gasket are: Loss of coolant with no apparent leak, white smoke from the exhaust, engine overheating, oil level over full, a grey foamy substa…nce on the under side of the oil fill cap, air bubbles escaping from the radiator, engine running, cap off.

No, the dip stick will normally be hot. Symptoms of a blow head gasket are loss of coolant with no apparent leak, oil level overfull, white smoke from the exhaust that has a s…weet smell, a white foamy substance on the underside of the oil fill cap, and air bubbles escaping from the radiator fill hole with cap off, engine running. If you suspect you have a blown head gasket STOP driving this vehicle now or you will do serious damage to the engine.

First and formost Raidiator cap. Yes believe it or not start there then when you are having the heads fixed be sure to change the water pump its the second Major cause. Third …is if your cooling fans stop working. Good Luck Almost always overheating is the cause for whatever reason. Low of coolant, failed water pump, defective cooling fan, stuck thermostat, clogged radiator, etc.

Head Gaskets and Valve Covers

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